How NASA got an Android handset ready to go into space

Rewiring hardware and software in the Nexus S to make it work on the ISS.

It’s what science fiction dreams are made of: brightly colored, sphere-shaped robots that float above the ground, controlled by a tiny computer brain. But it isn't fiction: it’s the SPHERES satellite, and its brain is an Android smartphone.

Two and a half years ago, the Human Exploration and Telerobotics Project (HET) equipped a trio of these floating robots with Nexus S handsets running Android Gingerbread. (HET is a project at NASA's Ames Research Center that uses SPHERES, which stands for “Synchronized Position Hold, Engage, Reorient, Experimental Satellites," and that project itself is called SmartSPHERES). Despite their name, these SPHERES aren't traditional satellites—they're currently being used inside the International Space Station (ISS) to investigate applications like telerobotic cameras and high-latency control, and to measure sound and radiation levels.

More generally, the Android phones will help HET test out news ways of sensing and modeling the ISS so that robots can eventually become an integral part of the space station's operations. Space exploration is still largely a human-controlled operation, but by equipping each of these self-contained satellites with their own Nexus S, the team has enabled them to navigate autonomously while researchers provide high-level commands from Earth. There are currently two Nexus S smartphones at work in the ISS right now.

Hardware upgrades for SPHERES aren't possible without flying completely new equipment up to the ISS, but adopting Android allowed some quick software fixes that would have otherwise been impossible. It took some time and quite a bit of tinkering before the handset was ready to go up in space, however, including some hardware hacking and careful measurements of the accelerometer's accuracy in space.

Why the Nexus S?

The Nexus S as attached to a SPHERES satellite at NASA Ames.

Florence Ion

The SPHERES have been in flight since 2006. They were designed by MIT for use on the ISS as an upgradable test bed for formation flight and movement in space, where they use compressed CO2 thrusters. The project had mainly served to try out experimental software, but the needs of the HET SmartSPHERES project soon exceeded the capabilities of the decade-old processor contained inside the satellites. "By connecting a smartphone, we can immediately make SPHERES more intelligent. With the smartphone, the SPHERES will have a built-in camera to take pictures and video, sensors to help conduct inspections, a powerful computing unit to make calculations, and a Wi-Fi connection that we will use to transfer data in real-time to the space station and mission control,” wrote DW Wheeler, lead engineer in the Intelligent Robots Group at NASA Ames.

"We knew of other projects that were using the Nexus One, and HTC had done some interesting things in that phone that didn't make it ideal for us,” Mark Micire, research scientist and project lead of the Intelligent Robotics Group, told Ars. “It has to do with [HTC's] battery technology—it has to be a proprietary battery or it won’t boot up.”

Micire and the team also figured out that the Nexus S would be much easier to disassemble. “You basically pop it open,” said Micire. “It’s literally six screws on the outside and it comes apart.” Samsung had also separated the circuit boards inside the Nexus S, which made it easier to navigate around the various components featured inside the phone. “We look [at the SPHERES] as a robot that needed a brain, and that’s where Android phones came in.”

Cellphone lobotomies

Enlarge/ Cellphone lobotomies can be tricky things, but in NASA's case it worked.

NASA

One of the biggest challenges of getting a manufacturer’s proprietary hardware to work with your own is not knowing exactly what’s inside. “When you go with something that already exists, there's a lot of reverse engineering that has to happen,” explained Micire. “Especially in the case of phones: as much as I love our phone manufacturers, they're not always forthcoming about what's actually under the hood.”

In this particular case, the Nexus S had to be forced into permanent airplane mode before it could go up into space, but that couldn't involve a software solution. "When you get on an airplane and they tell you that you have to put it into airplane mode because it'll cause interference with the avionics and stuff—same things on ISS, except they require it to be a hardware switch," said Micire. At the time, before the phone had even premiered, iFixit posted its teardown of the Nexus S. Micire and his team were able to essentially use the high-resolution photos on the site to figure out which chip they had to disengage to disable the cellphone capabilities of the phone. They then waited in line on launch day to secure two phones so that they could perform their own “cellphone lobotomies” to physically remove the offending component. “We almost destroyed the first phone, but by the second phone we figured out which chip to pull,” recalled Micire. “It [was the] TXRX amplifier.”

From there, all the team had to do was test the phone to prove to the flight safety crew that it wouldn't cause interference on station. It passed. “The phone is none the wiser,” said Micire. “It just thinks it doesn't have cell phone service.”

Space only takes AA batteries

Micire and his team also had to figure out how to power up the phone without using a lithium-ion battery pack. “We were told very early on that getting a lithium-ion battery certified for the station was going to probably be greater than two years,” he explained. But the team had only two years to get this project off the ground.

Alkaline batteries had already been approved for space travel because they degrade “more nicely,” as Micire put it. Rather than explode and catch on fire, alkaline batteries will instead leak electrolyte fluid, which is easier to contain. The team on the Intelligent Robotics Group developed a battery pack for the Nexus S that would replace the lithium ion one with six AA batteries. The pack is then wrapped in a felt-like material that is specifically made to absorb any leakage that might occur, and a few Velcro patches are attached to it so that it can stay fixed to the SPHERES.

Enlarge/ A closer look at the AA battery pack strapped on to the Nexus S.

NASA

The cellular chip and battery pack weren't the only necessary hardware hacks. If the Nexus One’s glass touchscreen were to shatter in space, the lack of gravity would leave all those broken shards of glass up in the air. It's not bare feet in microgravity the Intelligent Robotics team is trying to protect: it's lungs. Micire explained that the scenario would be hazardous. “Those tiny little shards are just floating within the ISS and now you have astronauts that are just breathing them in."

The team figured out that they could use a type of Teflon tape to cover up the chassis of the Nexus S to simultaneously protect the phone and contain any broken pieces from floating about. “You kind of have to take the world that we live in and rework all of the engineering requirements,” Micire reflected. “I never would have thought of broken glass as an inhalant.”

Dealing with drivers—and sensors

The Nexus S runs an app that records activity on the gyroscope, accelerometer, and 3D compass.

Florence Ion

As with all types of devices, drivers can be the most finicky part of getting a project up and running. There were a multitude of benefits for the team if it stuck with Android’s Nexus line of phones, the most obvious being that there weren't any setbacks that might come with dealing with customizations performed by OEM manufacturers. “With the Nexus line of phones, you get the full Android open source release source code base—you don’t get that with a lot of the other Android platforms out there,” said Micire. He explained that if it hadn't been for the “pure” Android experience, the team wouldn't have been able to get around some of the driver issues that plague other Android handsets.

One of the issues was getting the phone to sync up with the computers in service on the ISS. The ISS currently uses ThinkPad T61p laptops loaded with Windows XP Service Park 3, and when the Nexus S was plugged into the notebooks, Windows asked for a driver disk—a bit of a problem when there is limited time to get official drivers approved. Micire and his team wrote an application that puts the phone into mass-storage mode without a USB cable needing to be plugged into it first. “We figured out the mass storage identified on these phones don’t require a driver—it just works,” said Micire. “Any other phone where we wouldn't have been able to do our own firmware build [would have left us] stuck with the default configuration.”

Before the Nexus S was ready to work, the performance of components like the gyroscope, accelerometer, and 3D compass also needed testing to confirm that they worked in microgravity. The team used a data logger application (which is actually available in the Google Play store) to record the data on the sensors and gather measurements. “[By recording] we were able to show that the sensors did behave as we expected; the accelerometer, it turns out, is not a sensor we can use very well on the SPHERES. But the rest of the sensors actually work really well.”

What's next?

Since the project began in late 2010, it's moved rather quickly despite some of the aforementioned software and hardware hassles. “We went from concept on the back of a napkin to full flight, to delivering our flight units in about six months,” said Micire. “Normally for any major piece of hardware that's going up on station, you're usually talking about a year to two-year process." The team was able to quickly get the project engineered and "fabbed up," as Micire put it, because they leveraged a lot of the stuff that was already built into the phones.

The Nexus S handsets made upgrading the “brain” of the SPHERES a less tedious process, not to mention a more affordable one. But despite NASA Ames’ close proximity to Google's headquarters—Moffett Field is only three miles away—the team at the Intelligent Robotics Group has to purchase their own handsets, though sometimes they do receive help when tinkering with Android from their friends at Google. “One of the catalysts for us being able to successfully downselect and use Android as successfully as we have is because Google is just over the fence from us here,” said Micire. “We created very early on this wonderful partnership with folks both inside and outside.”

The Intelligent Robotics Group is currently looking at building the next generation of the Smart SPHERES with a couple of Nexus 4 handsets they have managed to secure. Micire mentioned that the Human Exploration Telerobotics project has also fostered a few relationships with different handset manufacturers for future development, though he was not at liberty to say who.

In the end, the project was possible due to Android’s usefulness beyond mobile phones. "We made the right decision by going with Android because the ability to remove the lithium battery and have it run off of alkaline batteries I think would have been a lot more difficult with the Apple products... and having it work without a driver under Windows XP," said Micire. Earlier he had mentioned how impressed he was by how Android was being embraced by the embedded developer community: "you just get so much that comes for free with the platform.” Micire later added: “It’s humbling to say that even NASA can’t outrun the advancements that are happening with the mobile phone.”

84 Reader Comments

Why use any sort of smartphone for this? Seems like they went to a lot of trouble to deal with things like the cell radio, the screen, the battery, etc. Wouldn't it have been easier to start with an Arduino board or something like that?

Why use any sort of smartphone for this? Seems like they went to a lot of trouble to deal with things like the cell radio, the screen, the battery, etc. Wouldn't it have been easier to start with an Arduino board or something like that?

Starting with a smartphone nets them several sensors at lower cost, as well as construction that already has low grade RF hardening. The huge benefit is the already integrated OS software. They get to deal with I/O at a very high level. Arduino and similar project boards would require a nice chunk of reinventing the wheel.

sad that the iPhone could not be used because they could not get (or make) an external battery pack for the iPhone, yet it is a legitimate reason for not using a superior phone (LOL, troll bait, but my Opinion) ... but funny thing, it isn't HTC that is the enemy, but Samsung, too bad for samsung, their phones are useless for this sort of thing...

So who is the winner?, Google, HTC, and the generic "not on samsung" andriod OS!... finally something that i can credit to andriod OS as a positive...

BTW, i am a fan of the iPhone, even though i do not own a phone, (iPod touch or iPad does not count lol)but i am thinking that if you want to be Different get the version of the HTC phone used in ths article (SPACE READY!!!, with mods!!!) or get a blackberry Z10.. poor blackberry, they finally produce an iPhone competitor and people aren't interested in it...

TL;DR. good for HTC!...

How exactly did HTC "win" in this scenario. The only HTC phone referenced in the article is the Nexus One which the team dismissed...and I'm not sure anyone would want to use that as their primary smart phone these days due to its age. I'm also not sure how Samsung's Nexus S was "useless for this sort of thing" when the entire article is dedicated to its usefulness (even if there may have been better solutions).

sad that the iPhone could not be used because they could not get (or make) an external battery pack for the iPhone, yet it is a legitimate reason for not using a superior phone

Did you actually read the article? They used an Android device for a variety of reasons, several of which involve modifying the firmware to better handle the environment it would be operating in. The battery pack was a minor issue related to the lithium batteries (which the iPhone uses as well). If you know how to get the source for iOS to change low level behavior, please let me know, because it would make a lot of things easier. Android on a Nexus device is a much better base for this type of work.

They basically wanted a custom hardware solution, but made off-the-shelf components work in a hacked fashion to cut costs and do (some) things better. The best kind of hacking. Though whether this is a viable solution as we scale up to include more robots in space, I'm not sure. Nonetheless, it is cool.

P.S. This has nothing to do with Apple vs. Android. They probably could've used any phone if they had various resources, money, time, etc, but decided to go with this one because it offered X number of benefits.

Are only alkalines used in space missions? No lipo or at least nimh? Energy density is crap for alkaline.

Li-Po was sort of answered in the article; it's lithium-based, so too dangerous. Not sure about the hazards of NiMH. Alkalines met the requirements of the mission. Wasn't it clear from the article that solutions that are obvious on the ground are not always a good idea in the vastly different environment of space?

Very cool, it'll be interesting to see what they can do with a Nexus 4. There is currently a pico-sat in orbit right now with a Nexus One as a tech demo to see how the phone deals with space environment.

I see more projects like these as you can get a lot of processing power in a very small power envelope for not a lot of money. Should work out pretty well for the tiny pico-sats if they can deal with the radiation and temps on orbit.

Are only alkalines used in space missions? No lipo or at least nimh? Energy density is crap for alkaline.

Li-Po was sort of answered in the article; it's lithium-based, so too dangerous. Not sure about the hazards of NiMH.

Well, according to Wikipedia there can be some issues if one battery in a set finishes discharging before the others, and NiMH batteries tend to self-discharge faster. Alkalines also have the advantage of an absolutely enormous production infrastructure and cheap prices, which I imagine were the main reason they were chosen over NiMH batteries if they were allowed.

It should also be emphasized a bit that lithium-ion batteries are not permitted on the ISS, not forbidden in space missions in general; a wide range of batteries are used in space missions depending on the particular mission profile expected and whether or not humans are onboard. Also, it's not even a blanket ban; as the article notes, Li-ion batteries could be certified for ISS use, it would just take a few years and probably a fair bit of engineering to mitigate the fire hazard. Because this was supposed to be a quick, cheap project, they simply chose not to bother.

EDIT: As a matter of fact, if you go to the page on Li-Po batteries on Wikipedia, the second image is of a battery stack that (according to the caption) was designed and built by Lockheed for NASA, here.

I assume they didn't specifically want a smartphone, they wanted a cheap mobile computing platform with software and hardware that could be easily modified. As the project started in 2010, they couldn't have got their hands on a Raspberry Pi, but that would definitely be a better choice now for a robot brain

The Pi also runs a smartphone SoC but the much lower cost, ease of hooking up all kinds of sensor hardware and the availability of straightforward Linux distros instead of Android makes more sense for this kind of project.

I assume they didn't specifically want a smartphone, they wanted a cheap mobile computing platform with software and hardware that could be easily modified. As the project started in 2010, they couldn't have got their hands on a Raspberry Pi, but that would definitely be a better choice now for a robot brain

The Pi also runs a smartphone SoC but the much lower cost, ease of hooking up all kinds of sensor hardware and the availability of straightforward Linux distros instead of Android makes more sense for this kind of project.

They didn't specifically want a smartphone. What they wanted, and what currently only exists in a smartphone, is a computing device with various spatial and kinetic sensors already attached, functioning, and capable of being worked with.

Raspberry Pi, or any other miniaturized computing device really, does not have those built-in sensors, complete with corresponding software that doesn't need to be tested and tinkered with. The elegance of the NASA approach is that they take a hardware set that already has 90% of what they needed, and perform minor but important modifications to make it work. Using a Pi or Beagle Board would mean they would have to buy the boards, screens, sensors, cameras, storage, and then get or write software for each of those subcomponents, and then figure out a way to make the thing talk to a Win XP laptop. With an android phone, all of the necessary hardware and software is there. To top it off, the source code is available, so that the NASA engineers can look at it and see what they need to modify.

It'll be interesting to see what kinds of modifications they'll do with the Nexus 4. Its lithium battery isn't easily removable, so maybe that means that they're planning far enough head with the next version that they'll be able to go through the lengthy certification process?

This is awesome. Smartphones are doubling in speed *every* year and billions are being poured into making them more and more aware of their location, environment, improving IO (Siri etc). Expect to see much more of this stuff.

As I said, this is awesome. I'm amazed google / Samsung don't already feature this prominently in their adverts.

Why use any sort of smartphone for this? Seems like they went to a lot of trouble to deal with things like the cell radio, the screen, the battery, etc. Wouldn't it have been easier to start with an Arduino board or something like that?

No, an Arduino is completely different than a phone in terms of capability. Had they started from scratch, they would have needed to build everyone on top of it.

In terms of the trouble they went through, it's pretty much trivial. Taking out the amplifier chip, attaching a new battery pack, and wrapping the phone in clear tape could easily be done in a day.

Wayzom wrote:

There are 100s of better choices. Since it does not appear Samsung or Google sponsored their project, I am not sure what they were thinking. Probably a PR stunt to help with money. "Look we are adapting off the shelf solutions instead of spending millions on proprietary ones." It is a good plan, poorly executed.

Uhh..why was it poorly executed? They needed a system with a capable processor, kinetic sensors, a convenient interface, and low power consumption. They found such a system, and finished the project in 6 months. What else can you get for under a thousand dollars that does that? You claim that there are "100's of better choices", so please list some of them..

"Aghhh! The screen is spinning around!" "Did you turn off screen rotation?"

Interesting all the different issues they have to deal with in space. Although I'm a bit surprised they wondered if accelerometers work in microgravity. That sounds like a pretty big physics fail, or they are just being extra cautious. I mean, every time you shake your phone up and down, or drop it, it goes through a zero-gravity transition, and you can see using any sensor-graphing application that the acceleration graph is continuous and correct as it passes through the weightlessness transition. How could microgravity POSSIBLY cause an accelerometer to fail, when an accelerometer is by definition a device for measuring acceleration, and weightlessness is simply the 0 point on that scale?

Before the Android vs iOS debate kicks off, it's worth noting that while the SmartSPHERES team chose an Android phone, the ISS crew routinely listens to music on iPods and they have iPads for things like easy access to procedures during maintenance activities and reading scripts for public affairs videos.

I have the suspicion of many here shutting up and accepting the fact that such device was used simply because it was superior, period. Yet those same people run on iDevices. In other words, as soon as somebody mentions anything about an Android phone better than it's opposite rivalry, they flip out and start down voting of desperation and lack of maturity. I'd say grow up and admit it,

"Aghhh! The screen is spinning around!" "Did you turn off screen rotation?"

Interesting all the different issues they have to deal with in space. Although I'm a bit surprised they wondered if accelerometers work in microgravity. That sounds like a pretty big physics fail, or they are just being extra cautious. I mean, every time you shake your phone up and down, or drop it, it goes through a zero-gravity transition, and you can see using any sensor-graphing application that the acceleration graph is continuous and correct as it passes through the weightlessness transition. How could microgravity POSSIBLY cause an accelerometer to fail, when an accelerometer is by definition a device for measuring acceleration, and weightlessness is simply the 0 point on that scale?

The problem with the accels is most likely a lack of fidelity for low accelerations, particularly while sensing gravitational acceleration CONSTANTLY. They're great for sensing when you drop your phone, turn it on its side, or give it a rough shake, but can they sense a 1-2 m/s^2 acceleration towards one side WHILE in freefall? Something tells me that's a bit above the price range for most smartphone sensors.

Of course they couldn't use an Apple product; they don't play nice with anything. My Apple MUSIC player made it grossly difficult to put MUSIC on it. And by grossly difficult I mean forcing you to use iTunes which sucks. It also wouldn't play nice with any DAAP streaming that wasn't again iTunes and after an update stopped syncing with my cars bluetooth head unit. Plus the home button stopped working when the warranty ran out. In conclusion Apple is overhyped.

but funny thing, it isn't HTC that is the enemy, but Samdensity, too bad for samsung, their phones are useless for this sort of thing...

Serious reading comprehension fail.Nexus S is a Samsung phone, you can even see their logo in the article photos. They also explain why the HTC Nexus could not be used.

The article was about adopting off the shelf solutions for space, not about phone brands. Pretty neat article.

Are only alkalines used in space missions? No lipo or at least nimh? Energy density is crap for alkaline.

They mentioned in the article that using lithium batteries would require an extensive testing and certification. They do use nickel hydride, lithium and other battery technologies in spacecraft but the lead-time needed for testing while using a proprietary battery is long. You've heard I'm sure about the Lithium-poly battery issues that Boeing is having with their Dreamliner, 787 and we all remember the stories of laptop lithium ion batteries catching fire. Imagine that happening inside the ISS. Both of those battery systems constitute "proprietary" batteries. They mentioned the IBM T61 laptops used on the ISS by the astronauts. The base battery for that laptop is nickel hydride. Some department at NASA probably has a large stash of those "obsolete" laptops with a pile of fresh, never flown-in-space laptop batteries so that NASA doesn't have to go through and re-certify another laptop and battery combination.

Off-the-shelf alkaline AA batteries have long been suitable for use inside habitable space on the ISS and other space craft. You might remember in Apollo13,(the movie) the image of the cassette player floating while playing a Johnny Cash tune as the batteries wound down. Alkaline AA batteries have been used for handheld equipment inside spacecraft since Gemini missions. Leaking electrolyte from lithium ion batteries is fairly toxic compared to alkaline batteries. For manned space missions you go with what has been proven safe, that has been tested extensively and is adequate for the task. "State of the art" for the space shuttles were CPUs based on Intel 486 processors since they were more resistant to cosmic rays and less likely "to flip a bit" if a memory or cpu register got hit with a cosmic ray particle.

NiMH batteries tend to self-discharge faster. Alkalines also have the advantage of an absolutely enormous production infrastructure and cheap prices, which I imagine were the main reason they were chosen over NiMH batteries if they were allowed.

NiMH have been available in low-self-discharge versions (Sanyo Eneloop/Tenergy Centura) for several years now, which gives them years of standby time.

Alkaline batteries are NOT CHEAP. They sell at prices of $0.50/pc versus $2/pc for NiMH-LSD, and the alkalines are significantly LOWER CAPACITY, so you're saving money by the 3rd recharge. At this point, it is massively irrational for consumers to buy disposable batteries.

As for NASA, NiMH is known to be immensely stable... You can charge them with unregulated power, and massively overcharge them, and not only will they not catch fire, but they will continue to work just fine (though frequent abuse/overcharging will shorten their life).

I'd be very curious to find out why NiMH isn't one of those technologies with blanket approval, like alkaline, since I'd expect it to be just as safe. Are they just extra cautious and require certification of anything that can be recharged?

How reliably are these non-radiation hardened phones going to perform? Were they tested inside the nearest nuclear reactor?

Consumer equipment doesn't include error checking for flipped bits in memory or CPU cache (ECC), while server-class computing hardware does. In the later case, while you might not always be able to recover from errors, you would at least know an error occurred, and restart the system from a non-corrupt state.

With phones like these, how do they handle the occasional random memory bits being flipped and corrupting their output? It certainly seems like using two of these devices in parallel, with some custom circuitry so they could constantly compare the output of each of their calculations, would make a lot more sense for a high radiation environment. Ditto for on-disk file checksums.

How much more money would it really have cost them to use a real, low power server, with enterprise-level reliability (RAS) features? I have seen a few servers based on low-power ATOM chips, which incidentally cost less than a Nexus phone, so it doesn't seem far-fetched that they could have found a comparable but more reliable solution for only perhaps a modest amount more money.

NiMH batteries tend to self-discharge faster. Alkalines also have the advantage of an absolutely enormous production infrastructure and cheap prices, which I imagine were the main reason they were chosen over NiMH batteries if they were allowed.

NiMH have been available in low-self-discharge versions (Sanyo Eneloop/Tenergy Centura) for several years now, which gives them years of standby time.

Alkaline batteries are NOT CHEAP. They sell at prices of $0.50/pc versus $2/pc for NiMH-LSD, and the alkalines are significantly LOWER CAPACITY, so you're saving money by the 3rd recharge. At this point, it is massively irrational for consumers to buy disposable batteries.

As for NASA, NiMH is known to be immensely stable... You can charge them with unregulated power, and massively overcharge them, and not only will they not catch fire, but they will continue to work just fine (though frequent abuse/overcharging will shorten their life).

I'd be very curious to find out why NiMH isn't one of those technologies with blanket approval, like alkaline, since I'd expect it to be just as safe. Are they just extra cautious and require certification of anything that can be recharged?

Heh, you just saved me a lot of typing. I did however log in for the first time in ages just to give you an upvote. :-)

As a flashlight nerd (yep, those exist, check out CandlePowerForums) I'm quite aware of the plentiful advantages of low self-discharge NiMH cells (especially Eneloops) over any alkaline cell on the market today.I was starting to get frustrated by the fact that every post asking about NiMHs this would get dismissed with the same argument about lithium batteries, which are different beasts entirely—clearly not suitable for the job.

Alkalines of any make tend to leak far more often than decent quality LSD NiMH cells, have higher capacities and a much more stable discharge current, so this point continues to baffle me for the time being.

did the goog-nix phone put up advertisements and track its location to report to the google gaggle and loves to learn more about what its used for? so, what's the security issues? When was the last time a cell phone battery made by a reputable company fail?

Its an interesting concept, using highly integrated mobile devices, and a stack of raspberry pi's likely could have been built for this 1/10th the price.

Love the article don't care for the pro-goog-nix hardware. seems they are so much more subject to security issues, unpredictable, subject to fails, and less reliable overall. But that's just my experience. Go raspberry pi.

Did you read the article?

Quote:

Micire and his team also had to figure out how to power up the phone without using a lithium-ion battery pack. “We were told very early on that getting a lithium-ion battery certified for the station was going to probably be greater than two years,” he explained. But the team had only two years to get this project off the ground.

Alkaline batteries had already been approved for space travel because they degrade “more nicely,” as Micire put it. Rather than explode and catch on fire, alkaline batteries will instead leak electrolyte fluid, which is easier to contain.

So there's the answer to your battery question. Next.

Android is open source; once Google has released the code, you can do whatever the heck you like with it. That's a big benefit for NASA; they don't have to build an OS from scratch. The smartphone, as everyone else has said, has tons of sensors a Raspberry Pi doesn't have; if you think you can tack on a small LCD, accelerometer, gyroscope, GPS sensor, camera, WiFi, and the other things needed to a Raspberry Pi plus a custom OS and the drivers necessary to run all of these sensors and apps to run the gear you want, and get it certified for space use within the same six months for the same or lower cost, I recommend you go for it.

I think you read the article, and being a fan of one product and not a fan of Google, you ignored what you didn't want to see and instead decided what you'd have liked to see done, which isn't nearly as feasible given engineering constraints involving space travel, time, and cost. A Raspberry Pi is an interesting piece of hardware, sure, but it doesn't come close to fulfilling NASA's needs without a whole lot of extras added, and a whole lot of extra labor hours and cost.

And using this article to bitch about Google's privacy practices is just absurd. The phone's radio was disabled; it's not communicating back to earth on cellular. Wifi may be used for communication within the ISS, but that's it.

I read the story too, and I got from it that they had a specific problem and found an ingenious and cost effective solution using commodity hardware. They also explained why they went with their particular solution, and even a bit about why they chose this particular handset over another.

At no point did I get upset that they didn't use an iPhone. I will confess, I did think that if they could have used an iPod touch, they wouldn't need to remove or disable the cell phone components. But it was also extremely obvious why they couldn't use that - they needed something open source, which is definitely not iOS! Overall, I think my appreciation of Apple will survive, and my appreciation of Android is just a bit stronger

Beyond the complete coolness of what they've done, there's one other thing that strikes me: once upon a time, the idea of having any consumer electronics gear used in our space program at all, let alone actually going to space, was just .. well, unthinkable. NASA certainly looked to the private sector for certain technologies and drove a lot of innovations in the process. But for the program itself, it was all tremendously expensive, point design, build-to-order contract stuff. Here, we have sort of the reverse; hacking and modding remarkably cheap consumer gear for the space program. (Yes, there were issues, such as with the batteries and glass. But still...)

Of course, I doubt that we'll ever see such things in use as controllers for truly critical systems, which will remain high end and ultra expensive, massively and intentionally over-engineered, and tested for years, if not decades, before being deployed. But they (we) have apparently realized that not every bit of kit up there warrants that expense. Good on them (us) for that.

This post actually describes the problem people have had with apple products for a long time, it is not easy to resolve problems if you want to use the phone in ways that Apple do not authorize. It is locked down and inaccessible for the most simple tasks like resolving driver problems.

I am glad this information was released to us all, and i am in no way demeaning apple , they have created a wonderful smartphone, but it is not as smart as phones running the android OS.

Now i just wonder if they would have similar problems with the windows 8 phones as i think they are locked down too. Maybe if the release a pro version windows phone that will trump android completely, maybe maybe not.

Great article Ms Ion. It's just a shame that some comment trolls saw it as an opportunity to push some very poorly-directed barrows, without applying the basic reading comprehension that would have given them the answers you supplied in the article.

Florence Ion / Florence was a former Reviews Editor at Ars, with a focus on Android, gadgets, and essential gear. She received a degree in journalism from San Francisco State University and lives in the Bay Area.